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Old 01-02-2021, 10:56 PM   #66 (permalink)
racprops
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Quote:
Originally Posted by EcoVan View Post
I am running the stock LT245-75r-16 tires (80psi), if that will help your calculations. These factory Bridgestones drive quite well and are very likely going to be replaced with the same when the time comes ( we've got about 47,000 miles on the van now). I upgraded the shocks to Ridetechs... the factory shocks were nearly useless when the van is loaded.

I am not sure what axle is has, but as I said before the drivetrain on this van is much bigger than that on my 2002 Ford e250 with the 5.4 gas v-8.

Well this is interesting, I am surprised to learn that ALL the 2017 vans come with a standard 3:42 rear end.

I cannot show what is special order but it is normally with a towing package they go up not down with the gear sets…so it would be very odd to get a lower that 3:42 and more likely to go up to a 3.73 or 4.11.


At 70MPH running with a 30.46 Tire with a 3.42 it would be 1849 RPMs, with a 3.08 it would be 1665, with 3.23 it would be 1746 and lastly with a 2:73 gear it would be 1476.


Note the lowest gear that GM makes and installs is the 3:08 so at best that would run at 1665. An 165 RPM tach error is very possible.


I found a place that shows a 2:73 as a special order… And that there is only a little difference between a 3:43 and say a 2:73. That is only 373 RPMs…BUT I will want that 373 RPMs.

Rich
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